#include <iostream>
using namespace std;
class Bool {
 private:
  bool b;
 public:
  inline Bool(bool b1){b=b1;}
  inline Bool operator!(){
    return Bool(!b);
}
  bool truth(){return b;} 
};

ostream& operator<<(ostream& output,  Bool B) {
  output << ((B.truth())?"true":"false");
  return output;  
}
